Stopped at a small restaurant for coffee yesterday and there was a BMW 1600 parked there. I had a quick look at the kickstand and noticed that the kickstand switch is similar to that on the 1800. I imagine that BMW does what Honda does for certain parts, make the design and source the parts. Can't be too many manufacturers of this side stand switch. To keep this short, I would think with some investigation that the 1600 BMW side stand switch may work just as well.
Cheers